With food trucks parked on streets from Portland, Maine, to Portland, Oregon, the thought of buying lunch from a vehicle has become something that's not just accepted, but practically de rigueur. But is it a viable option for buying a new dress? A handful of boutique owners are betting that among trendsetters, the answer is yes. In Boston, Amy Chase sells her vintage finds from inside her sleek silver trailer. Customers can keep track of the roving store, named Haberdash Vintage, by checking the website for its hours and coordinates. (Those not able to spend their day tracking down the trailer can also purchase pieces online.)

In New York, you could once dig through Tiffany Nicole's collection of vintage Versace and Valentino in her brick-and-mortar store in Soho; now, she's moved herself and her stock to Bushwick, taking over a 1972 Continental and renaming the "space" Mobile Vintage Shop. Her location—for now—is across the street from Roberta's, a cult favorite pizza restaurant among Brooklyn's hipsters.

Then there's Portland, Oregon, arguably the originator of the food truck trend. The city has not one, but two different vehicular boutiques. Wanderlust, run by Dan and Vanessa Lurie, features both thrifted finds and pieces by local designers. The duo regularly crosses the city with their 1969 Cardinal Deluxe trailer in tow, updating customers on their location via Twitter. And while Lodekka might not be portable—its 1965 double-decker bus is permanently parked—you can still shop for vintage clothing and homewares from inside the vehicle.

Anyone still not convinced that the future in retail's mobile might want to pay a visit to the party Wanderlust and Lodekka are jointly throwing this Saturday. Besides a fashion show and big discounts on merchandise (Wanderlust is offering 20% off all items), there will also be games of bocce, beer on tap, and burgers served up by—what else?—a beloved Portland food truck.